As disclosed in a patent document, Japanese Patent Laid-Open No. 2002-157165 (patent document 1) listed below, when a data overwriter overwrites data stored in one of the plurality of data processing devices, the data overwriter must first identify a “target” data processing device, or a data overwrite object device, in which device the stored data is overwritten by the data overwriter. Overwrite of the data may also be understood as rewrite of the data.
For example, when the plurality of data processing devices are connected to a network, each of the plurality of data processing devices may have a unique communication ID for their identities, and such communication ID may be used to identify a “target” device, i.e., the data overwrite object device.
However, if a unique communication ID is assigned to each of the data processing devices (i.e., if all data processing devices have respectively different communication IDs), the shortage of the communication IDs may occur.